As usual for me, my view of history is in relation to rodents. Before the discovery of the "new world", felt became a valuable material especially as Europe and Asia were experiencing a mini-ice age. This resulted in the killing of beavers all over Europe and Asia. With the marked drop in the water table of many forests, the species of trees changed and the resulting climate effects. The new war of the oceans between France, Spain, and England as the new world was discovered brought about the cutting down of coastal forests for ship building. Both glass and steel were discovered and the demand for charcoal to create this glass and steel caused a very large portion of Europe's forests to be cut down. The newly cleared land was developed for agriculture and caused the spread of the invasive Rattus norvegicus ("brown" rats) which helped spread the fleas and bacteria (Y. pestis) that spread the "black death" plague. As is evidenced by the sudden loss of a large number of species of ground squirrel and prairie dog species along with continued die-offs (in North America in recent history and current problems), the plague was also devastating to many of Europe's fossorial rodents. This resulted in even lower water tables and historic notes of lakes and rivers drying up. With less trees, fuel became expensive until coal was discovered as a viable replacement for charcoal. Evolutionists like to cite the change of color of some moth species to match the soot of the start of the industrial revolution and I will stop there.

Pre-coal anthropogenic climate factors were localized and small in comparison with today. Deforestation was mainly it and solar variation was a larger effect than human burning and deforestation. In America, the introduction of horses led to easier taking of animals and migrations for tribes. Tribes who sometimes used prairie and forest fires to get game, or move them to a kill point. Mountain men took beavers to near extinction until felt was no longer in style, and other animal furs until more wool and cotton were produced. Early settlers , and later ones , too, deforested vast tracts. The post coal industrial revolution it drove was the beginning of a stimulated human population with steamships able to bring food to places where they couldn't before and in new types of food. Then oil was discovered and it increased more. For at least 1.1 million years the atmospheric CO2 varied, usually sedately, between 180 and 280 ppm. There were no exact measurements of it then, but it was estimated to be near the high side at 275ppm at the start of human geometrically increasing HGHGs, now just over 395 ppm and 400 ppm in the Arctic, triggering tundra methane releases rising geometrically.Before fossil fuels, the deforestation rate was small, but now we have cut down or burned 57% of rainforests. The US is down to about 1% of old growth forests. Pre coal, the rainforests and oceanic phytoplankton absorbed variations in CO2, and provided over 80% of the Earth's oxygen. Now, CO2 acidification of the oceans has killed off 40% of the phytoplankton.Many human tribes were not gentle on the biosphere before coal. Some had stewardship in their religions or philosophies. When the former discovered coal and oil, they couldn't think like the others and use this resource at its natural regeneration rate, and didn't really try to know it at first. The others had the wisdom passed down by elders to guide them in sustainability.Pre-coal, natural forces on climate far outweighed human effects. When it was colder, humans burned more and took more furs, but it was still within the planetary absorption ability. This all ended some time after fossil fuels became widely burned and geometric population growth started. In the past, the Sahara was a savanna with many rivers. Natural climate change brought an end to it and people adapted or migrated. People adapted during the last ice age and migrated first over water to the Americas, following the oceanic ice edge. Before that in the south where it was still warm, they traveled over exposed land and used boats and rafts for voyages to other lands in sight, like Australia. During the previous interglacial they first left Africa when it was warm elsewhere on land. The development of tools and clothes gave them more success with variable climate in the temperate zone.Rats followed humans for food scraps(later grain stocks), along with cats and dogs who became friendly and controlled the rats.Found this from 2005 of interest:"The scientific consensus that human actions first began to have a warming effect on the earth's climate within the past century has become part of the public perception as well. With the advent of coal-burning factories and power plants, industrial societies began releasing carbon dioxide (CO2) and other greenhouse gases into the air. Later, motor vehicles added to such emissions. In this scenario, those of us who have lived during the industrial era are responsible not only for the gas buildup in the atmosphere but also for at least part of the accompanying global warming trend. Now, though, it seems our ancient agrarian ancestors may have begun adding these gases to the atmosphere many millennia ago, thereby altering the earth's climate long before anyone thought.

New(2005) evidence suggests that concentrations of CO2 started rising about 8,000 years ago, even though natural trends indicate they should have been dropping. Some 3,000 years later the same thing happened to methane, another heat-trapping gas. The consequences of these surprising rises have been profound. Without them, current temperatures in northern parts of North America and Europe would be cooler by three to four degrees Celsius--enough to make agriculture difficult. In addition, an incipient ice age--marked by the appearance of small ice caps--would probably have begun several thousand years ago in parts of northeastern Canada. Instead the earth's climate has remained relatively warm and stable in recent millennia." From Scientific American archives. screw snow the denialist maniac, may he rot in hell for his delay tactics toward emissions reductions.http://dieoff.org/peruse, my dear

_________________"With every decision, think seven generations ahead of the consequences of your actions" Ute rule of life.“We do not inherit the earth from our ancestors; we borrow it from our children”― Chief Seattle“Those Who Have the Privilege to Know Have the Duty to Act”…Albert Einstein

Looks like you didn't come back and see it above.Found this from 2005 of interest:"The scientific consensus that human actions first began to have a warming effect on the earth's climate within the past century has become part of the public perception as well. With the advent of coal-burning factories and power plants, industrial societies began releasing carbon dioxide (CO2) and other greenhouse gases into the air. Later, motor vehicles added to such emissions. In this scenario, those of us who have lived during the industrial era are responsible not only for the gas buildup in the atmosphere but also for at least part of the accompanying global warming trend. Now, though, it seems our ancient agrarian ancestors may have begun adding these gases to the atmosphere many millennia ago, thereby altering the earth's climate long before anyone thought.

New(2005) evidence suggests that concentrations of CO2 started rising about 8,000 years ago, even though natural trends indicate they should have been dropping. Some 3,000 years later the same thing happened to methane, another heat-trapping gas. The consequences of these surprising rises have been profound. Without them, current temperatures in northern parts of North America and Europe would be cooler by three to four degrees Celsius--enough to make agriculture difficult. In addition, an incipient ice age--marked by the appearance of small ice caps--would probably have begun several thousand years ago in parts of northeastern Canada. Instead the earth's climate has remained relatively warm and stable in recent millennia." From Scientific American archives.AGW was absolutely irrefutable since 2005, yet denialists have kept governments from meaningful changes, and people in ignorance. It was really well known since the late 1980s, when action to start a transition away from fossil fuels should have been taken.Of course, if overpopulation would have been dealt with in the late 1960s, it would have been less critical to future climate, the present rapid depletion and pollution rates.

_________________"With every decision, think seven generations ahead of the consequences of your actions" Ute rule of life.“We do not inherit the earth from our ancestors; we borrow it from our children”― Chief Seattle“Those Who Have the Privilege to Know Have the Duty to Act”…Albert Einstein

Looks like you didn't come back and see it above.Found this from 2005 of interest:"...New(2005) evidence suggests that concentrations of CO2 started rising about 8,000 years ago, even though natural trends indicate they should have been dropping. Some 3,000 years later the same thing happened to methane, another heat-trapping gas.

I suspect this methane came from thawing permafrost that was frozen from the last ice age. Evidence of North American native habitation suggests that they did not live in much of Canada and the northern USA until recently and I suspect the arctic-like treeless grass areas did not support as much permanent wildlife and thus limited the humans to coastal areas (aquatic animals to eat) and nomadic groups that migrated with the grass-eaters. They are having to use refrigeration units on many of the supports of the Alaska pipeline due to the melting permafrost.

evidence suggests that concentrations of CO2 started rising about 8,000 years ago, even though natural trends indicate they should have been dropping. Some 3,000 years later the same thing happened to methane, another heat-trapping gas. The consequences of these surprising rises have been profound. Without them, current temperatures in northern parts of North America and Europe would be cooler by three to four degrees Celsius--enough to make agriculture difficult. In addition, an incipient ice age--marked by the appearance of small ice caps--would probably have begun several thousand years ago in parts of northeastern Canada. Instead the earth's climate has remained relatively warm and stable in recent millennia." From Scientific American archives.Clearing land, slash and burn, more rotting vegetation, more methane from animal husbandry. That is what they are talking about. Some methane from thawing southern tundras could have added methane, but nothing near the geometric rates of today.The point is that in especially the last 2000 years there was a cooling trend as the Earth's axis tipped more and the orbit around the sun became more elliptical. The ice age should have started in 1500 years or so. Now, because of humans burning forests, huge amount of agriculture, coal fired power and smelting plants, fossil fuel burning for transport, et al from gross overpopulation started with fossil fuels especially oil, leads to a very different world than what was supposed to be in 1500 years. Instead of the beginning ice age cycle as has happened in recent geologic history every 100K years (85-90K ice age with 10-15K interglacial), it will be worse than PETM by far. Then it was 10x slower and +25*F with 160-180 K years to start back with species increase from a loss of 30% to what it had been, over the next nearly 3 million years.This one will be more like +29*F, by 1500 years from now with 85-90% species loss, a 200K+ recovery and 3 Million years to beginning interglacial species diversity. It is hard to even imagine the people that caused this lack of foresight are even in the same species as we are. No morals as far as I can tell, except greed.

_________________"With every decision, think seven generations ahead of the consequences of your actions" Ute rule of life.“We do not inherit the earth from our ancestors; we borrow it from our children”― Chief Seattle“Those Who Have the Privilege to Know Have the Duty to Act”…Albert Einstein

I don't have scientific numbers for any of this it's just initial thoughts;

The significant changes to the earth done by hunanity pre-industrialisation are due to agriculture. The biggest would be the initial spread of farming in the stone age. Howeverthe most sudden would probably be the dieing off of the human population of the Americas just after the place was contacted by European diseases. In the jungles this would have resulted in death rates even more horrific than the Misissippi river civilisation where all trace of them vanished except their man made hills. The jungle is less kind to retaining arceology.

However any such event would be extreemly slight in comparison with the amount of fossil fuel we burn today so for CO2 levels if the effects of pre-industrial humanity are at all there then we should have burnt up by now.

Sorry the climate cannot be that sensitive. Unless you can give numbers which show otherwise.

I don't have scientific numbers for any of this it's just initial thoughts;

The significant changes to the earth done by hunanity pre-industrialisation are due to agriculture. The biggest would be the initial spread of farming in the stone age. Howeverthe most sudden would probably be the dieing off of the human population of the Americas just after the place was contacted by European diseases. In the jungles this would have resulted in death rates even more horrific than the Misissippi river civilisation where all trace of them vanished except their man made hills. The jungle is less kind to retaining arceology.

However any such event would be extreemly slight in comparison with the amount of fossil fuel we burn today so for CO2 levels if the effects of pre-industrial humanity are at all there then we should have burnt up by now.

Sorry the climate cannot be that sensitive. Unless you can give numbers which show otherwise.

We have changed the carbon sinks in our climate including preindustrialization. The effect wasn't large compared to today.

^ Yes, that's thepoint. We have changed the carbon cycle a bit in pre-industrial times but if that had any effect then we should be boiling now becaquse the effect we now have on carbon is so much more. Since we have not boiled the world then we had no significant effect on temperature through CO2 before industrilisation.

^ Yes, that's thepoint. We have changed the carbon cycle a bit in pre-industrial times but if that had any effect then we should be boiling now becaquse the effect we now have on carbon is so much more. Since we have not boiled the world then we had no significant effect on temperature through CO2 before industrilisation.

This makes no sense. If we had a small effect in pre-industrial times and we have increased the ways in which we cause such an effect significantly we then have a larger impact now. There is no logical reason to conclude we should or would be "boiling" if we had a small effect in the pre-industrial time and have a larger effect now. You changed from "any effect" to "significant effect" which negated any attempt at logic.

_________________With friends like Guido, you will not have enemies for long.

“Intellect is invisible to the man who has none” Arthur Schopenhauer

"The difference between genius and stupidity is that genius has its limits."Albert Einstein

^ The point is that we have a small almost un-noticable effect now which is it's self disputed.

If there was any effect from the tiny pre-industrial man made changes to the atmosphere then the effect of our present industry would be massive. Since it isn't having a large effect ( at least yet ) then the pre-industrial effect must be as close to zero as makes no difference.

^ Yes, that's thepoint. We have changed the carbon cycle a bit in pre-industrial times but if that had any effect then we should be boiling now becaquse the effect we now have on carbon is so much more. Since we have not boiled the world then we had no significant effect on temperature through CO2 before industrilisation.

Did you miss the part where it stated that we'd be 3-4 degrees cooler now had it not been for actions of pre-industrial humans, and that agriculture in North America would have been difficult as a result? Even without us boiling now, that's a profound difference from present day conditions.

^ The point is that we have a small almost un-noticable effect now which is it's self disputed.

The effect is not that small nor is it almost un-noticable now.

Quote:

If there was any effect from the tiny pre-industrial man made changes to the atmosphere then the effect of our present industry would be massive.

Not really, but that seems to be the spin you wish to put on it. Even if we cannot determine an effect through measurments does not mean there is no effect, just that the measurements were not precise enough to detect it or it was not large enough to be clearly determined above the noise level of the system. That is the same whether you are discussing climate, medicine, compound analysis, or even carpentry.

Quote:

Since it isn't having a large effect ( at least yet ) then the pre-industrial effect must be as close to zero as makes no difference.

Is it now that cumulative effects would be discussed?

_________________With friends like Guido, you will not have enemies for long.

“Intellect is invisible to the man who has none” Arthur Schopenhauer

"The difference between genius and stupidity is that genius has its limits."Albert Einstein

So the per-coal effect of humanity on the world temperature was a 3-4 degree warming. (hmmmm, no)

This happened without catastrophic sea level rises. But has allowed us to practice agriculture over a lot of land we wouldn't.

The effect of our present industry will be a 3-4 degree warming (c presumably?).

This will cause the sea to swollow the land and be absolutley catastrophic with many nations being entirely wiped out. Not.

Unfortunately, the world doesn't work in the same one-dimensional manner in which you process information here. What's interesting is that you clearly considered more than one in an adjacent thread, simultaneously accounting for both temperature and altitude. Is this out of convenience or a genuine mental block?